Vehicular vision system with undercarriage cameras

ABSTRACT

A vehicular vision system includes an electronic control unit (ECU) disposed at a vehicle and including an image processor that processes image data captured by at least one camera of the vehicle. An under-trailer camera is disposed at an underside of a trailer hitched to the vehicle. The under-trailer camera has a field of view under the trailer that includes a ground surface under the trailer that is traveled over by the trailer. The under-trailer camera captures image data as the vehicle and trailer are moving. The ECU, responsive to processing of image data captured by the under-trailer camera, detects an object under the trailer and determines that the detected object under the trailer is greater than a threshold size. The ECU, responsive to determination that the detected object under the trailer is greater than the threshold size, generates an output.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 15/929,568, filed May 11, 2020, now U.S. Pat. No. 10,906,493,which is a continuation of U.S. patent application Ser. No. 16/177,540,filed Nov. 1, 2018, now U.S. Pat. No. 10,647,282, which claims thefiling benefits of U.S. provisional application Ser. No. 62/581,937,filed Nov. 6, 2017, which is hereby incorporated herein by reference inits entirety.

FIELD OF THE INVENTION

The present invention relates generally to a vehicle vision system for avehicle and, more particularly, to a vehicle vision system that utilizesone or more cameras at a vehicle.

BACKGROUND OF THE INVENTION

Use of imaging sensors in vehicle imaging systems is common and known.Examples of such known systems are described in U.S. Pat. Nos.5,949,331; 5,670,935 and/or 5,550,677, which are hereby incorporatedherein by reference in their entireties.

SUMMARY OF THE INVENTION

The present invention provides a driver assistance system or visionsystem or imaging system for a vehicle that utilizes a plurality camerasto capture image data representative of images exterior of the vehicle,and provides undercarriage cameras to capture image data representativeof obstacles, rough terrain, drop-offs or the like at or near thevehicle (and/or a trailer towed by the vehicle). The system may processcaptured image data to detect obstacles or rough terrain or the like,and/or the system may display images derived from the captured imagedata to display the area under the vehicle to the driver operating thevehicle.

These and other objects, advantages, purposes and features of thepresent invention will become apparent upon review of the followingspecification in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of a vehicle with a vision system thatincorporates cameras in accordance with the present invention;

FIG. 2 is a plan view of the vehicle, shown towing a trailer, and shownwith undercarriage cameras at the vehicle and trailer in accordance withthe present invention; and

FIG. 3 is a side elevation of the vehicle of FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

A vehicle vision system and/or driver assist system and/or objectdetection system and/or alert system operates to capture images exteriorof the vehicle and may process the captured image data to display imagesand to detect objects at or near the vehicle and in the predicted pathof the vehicle, such as to assist a driver of the vehicle in maneuveringthe vehicle in a rearward direction. The vision system includes an imageprocessor or image processing system that is operable to receive imagedata from one or more cameras and provide an output to a display devicefor displaying images representative of the captured image data.Optionally, the vision system may provide display, such as a rearviewdisplay or a top down or bird's eye or surround view display or thelike.

Referring now to the drawings and the illustrative embodiments depictedtherein, a vehicle 10 includes an imaging system or vision system 12that includes at least one exterior viewing imaging sensor or camera,such as a rearward viewing imaging sensor or camera 14 a (and the systemmay optionally include multiple exterior viewing imaging sensors orcameras, such as a forward viewing camera 14 b at the front (or at thewindshield) of the vehicle, and a sideward/rearward viewing camera 14 c,14 d at respective sides of the vehicle), which captures images exteriorof the vehicle, with the camera having a lens for focusing images at oronto an imaging array or imaging plane or imager of the camera (FIG. 1).Optionally, a forward viewing camera may be disposed at the windshieldof the vehicle and view through the windshield and forward of thevehicle, such as for a machine vision system (such as for traffic signrecognition, headlamp control, pedestrian detection, collisionavoidance, lane marker detection and/or the like). The vision system 12includes a control or electronic control unit (ECU) or processor 18 thatis operable to process image data captured by the camera or cameras andmay detect objects or the like and/or provide displayed images at adisplay device 16 for viewing by the driver of the vehicle (althoughshown in FIG. 1 as being part of or incorporated in or at an interiorrearview mirror assembly 20 of the vehicle, the control and/or thedisplay device may be disposed elsewhere at or in the vehicle). The datatransfer or signal communication from the camera to the ECU may compriseany suitable data or communication link, such as a vehicle network busor the like of the equipped vehicle.

With the exterior surround view cameras of FIG. 1, there is limited orno view under the vehicle carriage, trailer carriage or at the tirelocation. Thus, no driver warning is provided of objects or hazards(such as rocks or rough terrain or such as any object that may bepresent on a road surface) under the vehicle. Such surround view camerasystems do not allow driver to view obstacles, rough terrain, drop-offsunder the vehicle/trailer at or near the vehicle/trailer tires. Thesurround view systems do not detect objects or hazards under thevehicle.

The vision system of the present invention provides auxiliaryundercarriage cameras that capture image data of the area(s) underneaththe vehicle and/or trailer so as to allow the driver of the vehicle toview images derived from the image data captured by the undercarriagecameras. For example, the system may provide the driver with a rearwardview of the front tires and a forward portion of the undercarriage (bydisplaying images derived from image data captured by camera A in FIG.2). The camera A is disposed at the front of the vehicle below the frontbumper and has a field of view rearward of the bumper and underneath thevehicle. Optionally, for example, the system may provide the driver witha forward view of the front tires and the forward portion of theundercarriage (by displaying images derived from image data captured bycamera B in FIG. 2).

The camera B is disposed at a generally middle region or under themid-point of the vehicle carriage and views forward and downwardtherefrom. Optionally, for example, the system may provide the driverwith a rearward view of the rear tires and of a rearward portion of theundercarriage (by displaying images derived from image data captured bycamera C in FIG. 2). The camera C is disposed at a generally middleregion or under the mid-point of the vehicle carriage and views rearwardand downward therefrom. The cameras A, B, C, D are disposed generallyalong a longitudinal centerline of the vehicle, with the cameras B, Cdisposed rearward of the front wheels of the vehicle and forward of therear wheels of the vehicle. Optionally, for example, the system mayprovide the driver with a forward view of the rear tires and of therearward portion of the undercarriage (by displaying images derived fromimage data captured by camera D in FIG. 2). The camera D is disposed atthe rear portion of the vehicle and below the rear of the carriage orrear bumper of the vehicle and views downward and at least forward ofthe rear bumper to view beneath the vehicle at the rear of the vehicle.

The system may operate to display the under-vehicle images responsive toa trigger or user input or the like. For example, a driver may actuate auser input so the display displays images derived from image datacaptured by the undercarriage camera(s), such as while driving overrough terrain or the like. Optionally, the system may automaticallydisplay images derived from image data captured by the undercarriagecamera(s) responsive to detection of an object (such as an objectgreater than a threshold size or height), such as rocks or rough terrainor the like (such as via processing of image data captured by one ormore undercarriage cameras). For example, if the system detects a largeobject (greater than a threshold height or size, such as an objecthaving a height of greater than, for example, 4 inches or 8 inches or 12inches, depending on the particular application of the system, andoptionally depending on the ground clearance for that vehicle) and/ordetects rough terrain that is at a threshold level of roughness orvariations (such as changes in height of the terrain that are greaterthan a threshold height over a predetermined distance, such as a changein height of, for example, a six inch rise or fall in height over a sixinch distance or 10 inch rise or fall in height over a 12 inch distanceor the like), the system may automatically display images so the driverof the vehicle is aware of the detected object/terrain and can react oradjust driving accordingly. Optionally, responsive to detection of asufficiently large object or sufficiently large change in terrain, thecontrol may control the vehicle (such as steering and/or braking of thevehicle) to avoid or mitigate impact with the detected object or terrainchange.

Optionally, the display device may display video images derived fromimage data captured by one or more underbody cameras, such as responsiveto actuation of a user input in the vehicle, so that the driver of thevehicle, as the vehicle is approaching an object or rough terrain, canactuate the display device to view the object(s) from underneath thevehicle to see if the objects/terrain are below the ground clearance ofthe vehicle. The control may generate an alert responsive todetermination that an object or terrain may impact the underside of thevehicle (i.e., has a height greater than the ground clearance of thevehicle). The alert may comprise an audible or visual alert, and maycomprise an electronically generated graphic overlay at the displayedimages, such as a graphic overlay that highlights the detected object(such as by coloring it red or flashing the displayed image or otherwisedemarcating the object or displayed images to draw the driver'sattention to a potential hazard).

Optionally, the system may include trailer-mounted cameras that aremounted at an undercarriage of a trailer that is being towed by thevehicle. When the trailer is connected or hitched to the vehicle, thetrailer cameras may communicate with (either via a wire or communicationbus or via wireless communication) with a controller of the vehicle.

When the trailer is connected to the vehicle, the system may, forexample, provide the driver with a forward view of the trailer bottomand/or the trailer hitch area (by displaying images derived from imagedata captured by camera E in FIG. 2). The camera E may be disposed atand under the trailer hitch, and/or at and under a middle region of thetrailer, and/or at and under and forward or rearward of a trailer axleand/or at and under a rear portion of the trailer and/or at any driverselected or customized location (such as any of the locations of camerasF in FIG. 2, with the viewing direction forward). Optionally, the systemmay, for example, provide the driver with a rearward view of the trailerbottom and/or the trailer hitch area (by displaying images derived fromimage data captured by one or more of cameras F in FIG. 2). The trailercamera(s) may be disposed at and under the trailer hitch, and/or at andunder a middle region of the trailer, and/or at and under and forward orrearward of a trailer axle and/or at and under a rear portion of thetrailer and/or at any driver selected or customized location (such as atany of the locations of cameras E and F in FIG. 2).

Optionally, the system may provide or display images to the driver of atop view of the ground area under the vehicle (and/or trailer), with thedisplayed images derived from image data captured by multiple camerasmounted under the vehicle (and/or trailer), with the image data stitchedor merged to form a composite image or top down view of the ground areaunder the vehicle and/or trailer. The system may process image datacaptured by multiple cameras mounted under the vehicle (and/or trailer)to perform object detection (via camera machine vision) and/or mayoperate in conjunction with one or more ultrasonic, radar or lidarsensors mounted under the vehicle (and/or trailer). The system may,responsive to processing of captured image data and/or responsive tounder-vehicle ultrasonic or radar or lidar sensors, generate a driverwarning based on objects detected under the vehicle. Optionally, thesystem may provide control of the steering and/or braking of the vehicleto avoid objects detected under the vehicle and may provide automaticbraking based on objects detected under the vehicle.

Optionally, the system may stitch or merge image data to provide variouscombined views for displaying at a display screen in the vehicle forviewing by the driver of the vehicle. For example, the system may stitchimage data captured by a rearward viewing camera (such as camera 14 a inFIG. 1) with one or more underbody cameras A, B, C, D to mitigate oreliminate blind spots of the area immediately adjacent to or under thevehicle. Optionally, for example, the system may stitch image datacaptured by a rearward viewing camera (such as camera 14 a in FIG. 1)with one or more underbody cameras A, B, C, D, E, F to provide enhancedviews during trailer backup maneuvering. Optionally, for example, thesystem may stitch image data captured by the surround view cameras (suchas cameras 14 a, 14 b, 14 c, 14 d in FIG. 1) with one or more underbodycameras A, B, C, D to provide enhanced 360 degree viewing (including theareas immediately adjacent to and/or under the vehicle). Optionally, forexample, the system may stitch image data captured by a forward viewingcamera (such as camera 14 b in FIG. 1) with one or more underbodycameras A, B, C, D, such as to provide enhanced viewing for off roaddriving purposes. Optionally, for example, the system may utilize orprocess image data captured by the underbody cameras for intelligentdriving and object detection and determination of ground clearanceand/or the like.

The system may also provide additional features on the displayed images.For example, the system may generate a vehicle footprint overlay or atrailer footprint overlay, and may allow the user to input the trailerdimensions and axle location(s) and the like so as to provide anaccurate or enhanced overlay of the trailer overlayed on the displayedground images captured by the undercarriage cameras and under trailercameras and the surround view cameras.

Optionally, the system may operate in a low power mode where thecamera(s) may be deactivated under certain driving conditions (such as,for example, highway driving conditions where the undercarriage viewsare not needed). Optionally, the system may utilize LED backlighting(via energizing one or more light emitting diodes or LEDs, such asvisible light emitting LEDs or near infrared light emitting LEDs) and/ornight vision incorporated into the undercarriage camera (s). The systemmay use two or more cameras for range/distance determination of objectspresent in the fields of views of the two or more cameras.

Optionally, the system may provide a cylindrical view display, which canbe panned or adjusted using the surround view camera(s) and/or theunderbody camera(s). Optionally, the system may provide a spherical viewdisplay, which can be panned or adjusted using the surround viewcamera(s) and/or the underbody camera(s). Optionally, the system mayprovide a panoramic view display using the surround view camera(s)and/or the underbody camera(s). The view or display selection may bebased on object detection and/or clearance detection (as detected viaprocessing image data captured by one or more of the surround viewcameras and/or the undercarriage cameras.

The system may detect objects or ground clearance via processing ofcaptured image data or via sensing via one or more underbody ultrasonicsensors, lidar sensors or radar sensors. Optionally, the system may alsoutilize a forward viewing camera mounted on top of the vehicle (such asat the top of a cab of a pickup truck or the like) for object/clearancedetection ahead and above the vehicle (such as for determining clearancefor the vehicle to pass through a tunnel or under a low bridge and/orthe like).

Thus, the system of the present invention provides a plurality ofunderbody or undercarriage cameras that capture image datarepresentative of the area under the vehicle. The system may displayvideo images derived from image data captured by the undercarriagecameras to assist the driver in seeing obstacles or rough terrain or thelike during a driving maneuver of the vehicle. Optionally, the systemmay merge or stitch image data captured by one or more undercarriagecameras with image data captured by one or more surround view cameras toprovide enhanced display of the area at and around the vehicle to assistthe driver in maneuvering the vehicle, such as during a reversing orparking maneuver. Optionally, the system may process image data capturedby the undercarriage cameras to detect obstacles or rough terrain or thelike, and may generate an alert to the driver (or may control thesteering and/or braking of the vehicle) so that the vehicle may avoidthe detected obstacle or the like.

The vision system may include a display for displaying images capturedby one or more of the exterior (forward, rearward, sideward) viewingcameras and/or one or more of the undercarriage cameras for viewing bythe driver of the vehicle while the driver is normally operating thevehicle. Optionally, for example, the vision system may include a videodisplay device, such as by utilizing aspects of the video displaysystems described in U.S. Pat. Nos. 5,530,240; 6,329,925; 7,855,755;7,626,749; 7,581,859; 7,446,650; 7,338,177; 7,274,501; 7,255,451;7,195,381; 7,184,190; 5,668,663; 5,724,187; 6,690,268; 7,370,983;7,329,013; 7,308,341; 7,289,037; 7,249,860; 7,004,593; 4,546,551;5,699,044; 4,953,305; 5,576,687; 5,632,092; 5,708,410; 5,737,226;5,802,727; 5,878,370; 6,087,953; 6,173,501; 6,222,460; 6,513,252 and/or6,642,851, and/or U.S. Publication Nos. US-2014-0022390;US-2012-0162427; US-2006-0050018 and/or US-2006-0061008, which are allhereby incorporated herein by reference in their entireties. Optionally,the vision system (utilizing the forward viewing camera and a rearwardviewing camera and other cameras disposed at the vehicle with exteriorfields of view) may be part of or may provide a display of a top-downview or bird's-eye view system of the vehicle or a surround view at thevehicle, such as by utilizing aspects of the vision systems described inInternational Publication Nos. WO 2010/099416; WO 2011/028686; WO2012/075250; WO 2013/019795; WO 2012/075250; WO 2012/145822; WO2013/081985; WO 2013/086249 and/or WO 2013/109869, and/or U.S.Publication No. US-2012-0162427, which are hereby incorporated herein byreference in their entireties.

The camera or sensor may comprise any suitable camera or sensor.Optionally, the camera may comprise a “smart camera” that includes theimaging sensor array and associated circuitry and image processingcircuitry and electrical connectors and the like as part of a cameramodule, such as by utilizing aspects of the vision systems described inInternational Publication Nos. WO 2013/081984 and/or WO 2013/081985,which are hereby incorporated herein by reference in their entireties.

The system includes an image processor operable to process image datacaptured by the camera or cameras, such as for detecting objects orother vehicles or pedestrians or the like in the field of view of one ormore of the cameras. For example, the image processor may comprise animage processing chip selected from the EYEQ™ family of image processingchips available from Mobileye Vision Technologies Ltd. of Jerusalem,Israel, and may include object detection software (such as the typesdescribed in U.S. Pat. Nos. 7,855,755; 7,720,580 and/or 7,038,577, whichare hereby incorporated herein by reference in their entireties), andmay analyze image data to detect vehicles and/or other objects.Responsive to such image processing, and when an object or other vehicleis detected, the system may generate an alert to the driver of thevehicle and/or may generate an overlay at the displayed image tohighlight or enhance display of the detected object or vehicle, in orderto enhance the driver's awareness of the detected object or vehicle orhazardous condition during a driving maneuver of the equipped vehicle.

The vehicle may include any type of sensor or sensors, such as imagingsensors or radar sensors or lidar sensors or ultrasonic sensors or thelike. The imaging sensor or camera may capture image data for imageprocessing and may comprise any suitable camera or sensing device, suchas, for example, a two dimensional array of a plurality of photosensorelements arranged in at least 640 columns and 480 rows (at least a640×480 imaging array, such as a megapixel imaging array or the like),with a respective lens focusing images onto respective portions of thearray. The photosensor array may comprise a plurality of photosensorelements arranged in a photosensor array having rows and columns.Preferably, the imaging array has at least 300,000 photosensor elementsor pixels, more preferably at least 500,000 photosensor elements orpixels and more preferably at least 1 million photosensor elements orpixels. The imaging array may capture color image data, such as viaspectral filtering at the array, such as via an RGB (red, green andblue) filter or via a red/red complement filter or such as via an RCC(red, clear, clear) filter or the like. The logic and control circuit ofthe imaging sensor may function in any known manner, and the imageprocessing and algorithmic processing may comprise any suitable meansfor processing the images and/or image data.

For example, the vision system and/or processing and/or camera and/orcircuitry may utilize aspects described in U.S. Pat. Nos. 9,233,641;9,146,898; 9,174,574; 9,090,234; 9,077,098; 8,818,042; 8,886,401;9,077,962; 9,068,390; 9,140,789; 9,092,986; 9,205,776; 8,917,169;8,694,224; 7,005,974; 5,760,962; 5,877,897; 5,796,094; 5,949,331;6,222,447; 6,302,545; 6,396,397; 6,498,620; 6,523,964; 6,611,202;6,201,642; 6,690,268; 6,717,610; 6,757,109; 6,802,617; 6,806,452;6,822,563; 6,891,563; 6,946,978; 7,859,565; 5,550,677; 5,670,935;6,636,258; 7,145,519; 7,161,616; 7,230,640; 7,248,283; 7,295,229;7,301,466; 7,592,928; 7,881,496; 7,720,580; 7,038,577; 6,882,287;5,929,786 and/or 5,786,772, and/or U.S. Publication Nos.US-2014-0340510; US-2014-0313339; US-2014-0347486; US-2014-0320658;US-2014-0336876; US-2014-0307095; US-2014-0327774; US-2014-0327772;US-2014-0320636; US-2014-0293057; US-2014-0309884; US-2014-0226012;US-2014-0293042; US-2014-0218535; US-2014-0218535; US-2014-0247354;US-2014-0247355; US-2014-0247352; US-2014-0232869; US-2014-0211009;US-2014-0160276; US-2014-0168437; US-2014-0168415; US-2014-0160291;US-2014-0152825; US-2014-0139676; US-2014-0138140; US-2014-0104426;US-2014-0098229; US-2014-0085472; US-2014-0067206; US-2014-0049646;US-2014-0052340; US-2014-0025240; US-2014-0028852; US-2014-005907;US-2013-0314503; US-2013-0298866; US-2013-0222593; US-2013-0300869;US-2013-0278769; US-2013-0258077; US-2013-0258077; US-2013-0242099;US-2013-0215271; US-2013-0141578 and/or US-2013-0002873, which are allhereby incorporated herein by reference in their entireties. The systemmay communicate with other communication systems via any suitable means,such as by utilizing aspects of the systems described in InternationalPublication Nos. WO 2010/144900; WO 2013/043661 and/or WO 2013/081985,and/or U.S. Pat. No. 9,126,525, which are hereby incorporated herein byreference in their entireties.

The system may utilize aspects of the trailering systems described inU.S. Pat. Nos. 9,085,261 and/or 6,690,268, and/or U.S. Publication Nos.US-2017-0254873; US-2017-0217372; US-2017-0050672; US-2015-0217693;US-2014-0160276; US-2014-0085472 and/or US-2015-0002670, which arehereby incorporated herein by reference in their entireties.

The system may utilize sensors, such as radar or lidar sensors or thelike. The sensing system may utilize aspects of the systems described inU.S. Pat. Nos. 9,753,121; 9,689,967; 9,599,702; 9,575,160; 9,146,898;9,036,026; 8,027,029; 8,013,780; 6,825,455; 7,053,357; 7,408,627;7,405,812; 7,379,163; 7,379,100; 7,375,803; 7,352,454; 7,340,077;7,321,111; 7,310,431; 7,283,213; 7,212,663; 7,203,356; 7,176,438;7,157,685; 6,919,549; 6,906,793; 6,876,775; 6,710,770; 6,690,354;6,678,039; 6,674,895 and/or 6,587,186, which are hereby incorporatedherein by reference in their entireties.

Changes and modifications in the specifically described embodiments canbe carried out without departing from the principles of the invention,which is intended to be limited only by the scope of the appendedclaims, as interpreted according to the principles of patent lawincluding the doctrine of equivalents.

1. A vehicular vision system, the vehicular vision system comprising: anelectronic control unit (ECU) disposed at a vehicle equipped with thevehicular vision system, the ECU comprising an image processor thatprocesses image data captured by at least one camera of the vehicle; anunder-trailer camera disposed at an underside of a trailer hitched tothe vehicle, wherein the under-trailer camera has a field of view underthe trailer that includes a ground surface under the trailer that istraveled over by the trailer, the under-trailer camera capturing imagedata as the vehicle and trailer are moving; wherein, with the trailerhitched to the vehicle, the ECU, responsive to processing of image datacaptured by the under-trailer camera, detects an object under thetrailer and determines that the detected object under the trailer isgreater than a threshold size; and wherein the ECU, responsive todetermination that the detected object under the trailer is greater thanthe threshold size, generates an output.
 2. The vehicular vision systemof claim 1, wherein the ECU generates the output to inform a driver ofthe vehicle of the detected object under the trailer.
 3. The vehicularvision system of claim 1, wherein the under-trailer camera is disposedrearward of wheels of the trailer.
 4. The vehicular vision system ofclaim 1, wherein the under-trailer camera is disposed forward of wheelsof the trailer.
 5. The vehicular vision system of claim 4, wherein theunder-trailer camera is disposed at a middle region of the trailer. 6.The vehicular vision system of claim 1, wherein the under-trailer camerais disposed along a centerline of the trailer.
 7. The vehicular visionsystem of claim 1, wherein the detected object comprises terrain underthe trailer, and wherein the ECU generates the output when the detectedobject has a height change greater than a threshold amount over apredetermined distance.
 8. The vehicular vision system of claim 1,comprising a display device disposed in the vehicle and viewable by adriver of the vehicle, wherein the display device, responsive at leastin part to the generated output, displays images derived from image datacaptured by the under-trailer camera.
 9. The vehicular vision system ofclaim 8, wherein the display device displays images derived from imagedata captured by the under-trailer camera responsive at least in part toa user input.
 10. The vehicular vision system of claim 8, wherein thedisplay device displays images derived from image data captured by theunder-trailer camera responsive to determination, via processing ofimage data captured by the under-trailer camera, of the detected objectunder the trailer.
 11. A vehicular vision system, the vehicular visionsystem comprising: an underbody camera disposed at an underside of abody of a vehicle equipped with the vehicular vision system, wherein aground surface under the body of the vehicle and being traveled over bythe vehicle is at least partially viewed by the underbody camera, theunderbody camera capturing image data as the vehicle is moving; aplurality of cameras disposed at the vehicle, wherein the plurality ofcameras at least comprises (i) a rear camera disposed at a rear portionof the vehicle and viewing at least rearward of the vehicle, (ii) adriver-side camera disposed at a driver side portion of the vehicle andviewing at least sideward of the vehicle, (iii) a passenger-side cameradisposed at a passenger side portion of the vehicle and viewing at leastsideward of the vehicle and (iv) a front camera disposed at a frontportion of the vehicle and viewing at least forward of the vehicle; anelectronic control module (ECU) disposed at the vehicle and comprisingan image processor that processes image data captured by the underbodycamera and the plurality of cameras; a display device disposed in thevehicle and viewable by a driver of the vehicle, wherein the displaydevice is operable to display video images derived from image datacaptured by the underbody camera and the plurality of cameras; wherein,responsive to an input, the vehicular vision system merges image datacaptured by the underbody camera with image data captured by at leastone of the cameras, and wherein the display device displays compositevideo images derived at least in part from the merged image data; andwherein the input comprises at least one selected from the groupconsisting of (i) actuation by the driver of a user input in thevehicle, (ii) detection by the ECU of an object under the body of thevehicle, (iii) detection by the ECU of an object under the body of thevehicle and determination by the ECU that the detected object has heightgreater than a threshold height, and (iv) detection by the ECU ofterrain under the body of the vehicle and determination by the ECU thatthe detected terrain has a height change greater than a threshold amountover a predetermined distance.
 12. The vehicular vision system of claim11, comprising a plurality of underbody cameras disposed at theunderside of the body of the vehicle, wherein image data captured by theplurality of underbody cameras is processed at the ECU.
 13. Thevehicular vision system of claim 11, wherein the underbody camera isdisposed rearward of front wheels of the vehicle and forward of rearwheels of the vehicle.
 14. The vehicular vision system of claim 13,wherein the underbody camera is disposed at a middle region of the bodyof the vehicle.
 15. The vehicular vision system of claim 11, wherein theunderbody camera is disposed along a centerline of the body of thevehicle.
 16. The vehicular vision system of claim 11, wherein theunderbody camera views at least forward, and wherein the ECU, viaprocessing of image data captured by the underbody camera, detects anobject forward of the underbody camera and determines that the detectedobject has height greater than a threshold height.
 17. The vehicularvision system of claim 11, wherein the underbody camera views at leastrearward, and wherein the ECU, via processing of image data captured bythe underbody camera, detects an object rearward of the underbody cameraand determines that the detected object has height greater than thethreshold height.
 18. The vehicular vision system of claim 11, whereinthe input comprises actuation by the driver of a user input in thevehicle.
 19. The vehicular vision system of claim 11, wherein the inputcomprises detection by the ECU of an object under the body of thevehicle.
 20. The vehicular vision system of claim 11, wherein the inputcomprises detection by the ECU of an object under the body of thevehicle and determination by the ECU that the detected object that hasheight greater than a threshold height.
 21. The vehicular vision systemof claim 11, wherein the input comprises determination by the ECU ofpresence of terrain under the body of the vehicle and determination bythe ECU that the detected terrain has a height change greater than athreshold amount over a predetermined distance.
 22. A vehicular visionsystem, the vehicular vision system comprising: an electronic controlunit (ECU) disposed at a vehicle equipped with the vehicular visionsystem, the ECU comprising an image processor that processes image datacaptured by a plurality of cameras disposed at the vehicle; wherein theplurality of cameras includes an underbody camera disposed at anunderside of a body of the vehicle, wherein a ground surface under thebody of the vehicle and being traveled over by the vehicle is at leastpartially viewed by the underbody camera, the underbody camera capturingimage data as the vehicle is moving; wherein the plurality of cameras atleast comprises (i) a rear camera disposed at a rear portion of thevehicle and viewing at least rearward of the vehicle, (ii) a driver-sidecamera disposed at a driver side portion of the vehicle and viewing atleast sideward of the vehicle, (iii) a passenger-side camera disposed ata passenger side portion of the vehicle and viewing at least sideward ofthe vehicle and (iv) a front camera disposed at a front portion of thevehicle and viewing at least forward of the vehicle; an under-trailercamera disposed at an underside of a trailer hitched to the vehicle,wherein the under-trailer camera has a field of view under the trailerthat includes a ground surface under the trailer that is traveled overby the trailer, the under-trailer camera capturing image data as thevehicle and trailer are moving; wherein, with the trailer hitched to thevehicle, the ECU, responsive to processing of image data captured by theunder-trailer camera and the underbody camera, detects an object underthe trailer or under the vehicle and determines that the detected objectunder the trailer or under the vehicle is greater than a threshold size;a display device disposed in the vehicle and viewable by a driver of thevehicle, wherein, with the trailer hitched to the vehicle, the displaydevice is operable to display video images derived from image datacaptured by the under-trailer camera and the plurality of cameras;wherein, responsive to an input, the vehicular vision system mergesimage data captured by the under-trailer camera with image data capturedby the underbody camera and with image data captured by at least oneother camera of the plurality of cameras, and wherein the display devicedisplays composite video images derived at least in part from the mergedimage data; and wherein the input comprises at least one selected fromthe group consisting of (i) actuation by the driver of a user input inthe vehicle, (ii) detection by the ECU of an object under the trailer orunder the vehicle, (iii) detection by the ECU of an object under thetrailer or under the vehicle and determination by the ECU that thedetected object has height greater than a threshold height, and (iv)detection by the ECU of terrain under the trailer or under the vehicleand determination by the ECU that the detected terrain has a heightchange greater than a threshold amount over a predetermined distance.23. The vehicular vision system of claim 22, comprising a plurality ofunderbody cameras disposed at the underside of the body of the vehicle,wherein image data captured by the plurality of underbody cameras isprocessed at the ECU.
 24. The vehicular vision system of claim 22,wherein the underbody camera is disposed rearward of front wheels of thevehicle and forward of rear wheels of the vehicle.
 25. The vehicularvision system of claim 22, wherein the underbody camera is disposedalong a centerline of the body of the vehicle.
 26. The vehicular visionsystem of claim 22, wherein the input comprises actuation by the driverof a user input in the vehicle.
 27. The vehicular vision system of claim22, wherein the input comprises detection by the ECU of an object underthe trailer or under the vehicle.
 28. The vehicular vision system ofclaim 22, wherein the input comprises detection by the ECU of an objectunder the trailer or under the vehicle and determination by the ECU thatthe detected object that has height greater than a threshold height. 29.The vehicular vision system of claim 22, wherein the input comprisesdetermination by the ECU of presence of terrain under the trailer orunder the vehicle and determination by the ECU that the detected terrainhas a height change greater than a threshold amount over a predetermineddistance.